Dyeing polyacrylonitrile with basic dyestuff and alkoxymethyl quaternary ammonium compounds

ABSTRACT

Fibrous material consisting at least predominantly of polyacrylonitrile is dyed in an aqueous dyebath containing a basic dyestuff and up to about 10 percent by weight of at least one alkoxymethyl quaternary ammonium compound as a decomposable retarder. An illustrative example of such a retarder is ntetradecyloxymethyltributylammonium chloride.

United States Patent 91 Komninos et al.

[451 Feb. 13, 1973 DYEING POLYACRYLONITRILE WITH BASIC DYESTUFF AND ALKOXYMETHYL QUATERNARY AMMONIUM COMPOUNDS Inventors: John Komninos, l9 Barnfield Court, Upper Saddle River, NJ. 07458; Peter Klemchuk, 148 Upland Rd., Yorktown Heights, NY. 10598; George Ham, 284 Pine Rd., Briarcliff Manor, N.Y. 105 I0 Filed: Nov. 27, 1970 Appl. No.2 93,479

Related U.S. Application Data Continuation-impart of Ser. No. 786,904, Dec. 26, 1968, abandoned.

us. CI. ..8/l69, 8/168, 8/172 Int. Cl. ..D06p 5/04, D06p 5/06 Field of Search ..8/84, 172, 177 AB, 173

Primary ExaminerGeorge F. Lesmes Assistant Examiner-4. P. Brammer Attorney-Karl F. Jorda [5 7] ABSTRACT Fibrous material consisting at least predominantly of polyacrylonitrile is dyed in an aqueous dyebath containing a basic dyestuff and up to about 10 percent by weight of at least one alkoxymethyl quaternary ammonium compound as a decomposable retarder. An i1- lustrative example of such a retarder is n-tetradecyloxymethyltributylammonium chloride.

12 Claims, No Drawings DYEING POLYACRYLONITRILE WITH BASIC DYESTUFF AND ALKOXYMETIIYL QUATERNARY AMMONIUM COMPOUNDS RELATED APPLICATION The present application is a continuation-in-part of Ser. No. 786,904, filed Dec. 26, l968 and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention-relates to a new and improved procedure for dyeing fibrous material and particularly, fibrous material consisting at least predominantly of polyacrylonitrile by a procedure involving contacting said fibrous material, in an aqueous dyebath, with at least one member of a group of alkoxymethyl quaternary ammonium compounds which acts as a retarding agent. It has been found that by the use of the retarders of the present invention, there is obtained a more uniform distribution of the dye on acrylic fibers and fabrics than has been hitherto possible. The retarding agents'may also function as migrating agents and may aid in achieving level dyeing through promoting dye transfer.

2. Description of the Prior Art Fibers of polyacrylonitrile and of acrylonitrile copolymers are being increasingly dyed with basic dyestuffs having a high affinity for the fiber; the dyestuffs consequently go on almost completely and very fast dyeings are obtained. However, because of the rapid absorption of the dyestuff due to its high affinity, this leads to uneven dyeings when the dyeing is effected in the temperature range of 185 F to boiling temperature and especially, in the temperature range of 194 to 205 F. This problem can only be remedied, in some cases, by careful temperature regulation i.e., slow increase of temperature during the dyeing.

In the dyeing of textiles, and this is meant to include synthetics such as, for example, nylon, acrylonitrile, and the like, certain substances generally referred to as dyeing assistants are added to the dye bath to promote or to control dyeing. Such substances aid in the achievement of uniform absorption of the dye by the fiber. The manner in which the level dyeing is accomplished depends, generally, upon the particular dyestuff in use and also upon the substance which is employed as a dyeing assistant. Usually, a dyeing assistant will aid in promoting level deposition of the dye on the fiber or fabric in several ways. For example, certain dyeing assistants will promote level dyeing by increasing the solubility of the dye in the bath. Other dyeing assistants however, will accomplish the desired result by delaying the absorption of the dye by the fiber. Finally, other dyeing assistants will function as such by aiding the dye to penetrate more readily the material to be colored. The expressions dye leveling agents" and dye retardant agents" are frequently used when referring to dyeing assistants. The aforesaid expressions are employed to denote compounds which promote level dyeing. However, the expression dye retardant agent is used most often in a more specific sense, namely, to designate compounds, which, when added to a dye bath, promote level dyeing by preventing rapid exhaustion of the bath. A dye retardant agent accomplishes this by decreasing the rate of absorption of the dye present in the dye bath.

with the anionic groups at lower temperatures, that is, at temperatures below about 180-200 F. The fiber,,

upon being brought to a temperature between about 180 and 200 F becomes soft or plastic and porous. The softened fiber provides easy and rapid access of dyes to many more dye sites. Therefore, the rate of dye strike is accelerated within a narrow temperature range. A further complication results from the high concentration of dye present in the bath at the critical strike temperature. The rate of dye strike is further accelerated when the'temperature is raised from l94-20 5 F. The dye/dye site complex once formed is insoluble, particularly at temperatures below ll90 F at which the access to dye sites are closed, thus locking in the dye. The locked-in dye is therefore rendered extremely fast to washing. The bond between the dye and the dye site is relatively strong at the dye temperature and consequently, levelling presents a problem. Generally, retardation has been the only means to accomplish level dyeings and retarders are employed to cause the rate of strike to become slower at the critical temperature i.e., between about and 200 F.

Two types of retarders have been generally used; the

first type is the cationic retarder and such a system functions by competing with the dye for the available dye sites. A cationic retarder has more affinity for the dye site and, due to its smaller molecular size, is able to precede the dye at slightly lower temperatures. As a result, less dye sites are available at temperatures between about 180 and 200 F and the shortage of sites causes the dye to seek out vacant sites and draw out of the bath evenly. It has been shown that with this retarder system, the dye strike from 200-206 F is extremely rapid and this further narrows an already dangerously narrow temperature range.

Cationic dyes per se may themselves be classified as retarders due to their ability to more or less permanently occupy a dye site. Self-retardation occurs only when the concentration of dye present in the bath is high in relation to available dye sites; hence deep shades require less retarder than light shades.

Since cationic retarders are nearly permanent in their occupancy of dye sites, they present a barrier to the movement of dye from a more heavily dyed area. Migration is, therefore, inhibited by the use of cationic retarders. Another disadvantage associated with the use of cationic retarders is that they further separate differential dyeing characteristics of cationics making the slow color dye slower relative to faster exhausting colors. Still another disadvantage is that the presence of the strong retarder, reduces the dye buildup and makes redyeing to darker repair shades difficult if not impossible. Then, it has been found that cationic retarders are dependent on dyestuff concentration and the less dye used the more retarder. will be necessary. Another criticism of the use of cationic retarders is that they block out cationic softener aftertreatments. In addition, cationic retarders usually work against or prevent migration because retained retarder blocks out transferring dye.

A second type of retarding agent used is an anionic retarder and such a system functions through the formation of a complex or anionic surfactant with the cationic dye. In order to prevent precipitation, the complex is stabilized by being held in a dispersed form in the bath by a nonionic surfactant. The larger size particle of the complex attaches itself to the fiber surface at temperatures even lower than that containing no retarder. ln this manner, the otherwise very narrow strike temperature range is widened. At sustained temperatures above 190 F, the complex dissociates slowly thus giving up the dye to the dye site uniformly. Unfortunately, the disassociation is not complete as a portion of thedispersed complexed dye remains associated throughout the entire dye cycle resulting in lower yields than those obtained by the use of cationic systems.

Further, anionic retarders allow only slightly better migration than cationic retarders and the major appeal of the former is in special areas where bulking shrinkage is otherwise inhibited or where cationic/anionic dye combinations are required for blends.

Another problem which must be contended with in dyeing procedures is migration and especially so when contending with the dyeing of acrylics. The temperatures required to migrate wool dyes are much lower than those needed for cationic dyes on acrylic fibers. It has been found that the temperature needed is high, that is, .above the boil and consequently, pressurized equipment is necessary. The use of such equipment represents a problem which dyers wish to avoid not only from the point of view of simplifying the process but also from the point of view of minimizing the cost. In addition, fabrics and particularly, acrylics, do not lend themselves to pressure dyeing.

In the dyeing procedure, the dyer is faced with the problem of a balance between retardation and migration since it is almost impossible to obtain both effects. The problem is further complicated by the fact that retarder systems, when used'at high concentrations, can nullify the beneficial effect of migration aids. For example, the retained or residual cationic retarder can block out the transferring dye. This effect is more evident at lower temperatures that is, at temperatures of about 180 F while at higher temperatures, i.e., temperatures of about 212 F, the cationic retarder causes somewhat less interference with migration. However, at no time within the temperature range of l802l2 F, are all of the dyesites available. Thus, attempts at black shade re-dyeing of bad lots, previously dyed in the presence of strong cationic retarders, have shown the permanence of at least some of the dye site/retarder linkage.

in the case of the use of anionic retarders, a similar problem exists although this problem is not quite as severe. The complex of dye and anionic surfactant once broken, leaves the excess anion active material in the bath and this material is free to complex with the dyestuff moving from the fiber into the bath and prevent, at least partially, a further exhaustion onto another dye site. Since the anionic retarder does not occupy dye sites, those anionic retarders of low dye concentration are more apt to receive transferred dye than in a cationic retarder system.

Therefore, if a migrating agent is included in the dyeing bath, it is then important, in order to secure the desired results, to significantly reduce the concentration of the retarding agent. The inverse relationship between retarder concentration and. depth of shade remains valid and a similar relationship must exist between the migrating agent and dye concentration.

The drawing rate of the baths containing migrating agents are more rapid'than those containing retarder' tarder and migrating agent and consequently, the

results are often poor.

Inorganic salts have been used as migrating agents but unfortunately, it was found that these salts had a stripping effect; the high concentration of the inorganic salts which entered into a dye bath prohibited complete exhaustion. Thus, although the inorganic salts are fairly inexpensive, the loss of dye yield is costly and consequently, the salts cannot be used as migrating agents.

Solvents have also been studied but it has been found that these substances apparently function in the fashion similar to that of the inorganic salts. in addition, deleterious effects on wet fastness were noted, in some cases.

Bayer German Pat. No. 1,123,286 discloses the treatment of polyacrylonitrile fabrics with a quaternary ammonium compound of the general formula wherein R R R R and R cover substituted aliphatic, aromatic, aryl aliphatic or hydroaromatic groups containing at least 8 carbon atoms and Z is an anion such as Cl, Br or CH SO The aforesaid R,, R R R and R can be substituted by halogen, hydroxy or nitro groups. While a countless number of quaternary ammonium compounds are covered by the aforesaid formula, only one compound has actually been illustrated, namely dodecyloxymethyldimethylbenzylammonium chloride, and on comparing this compound with compounds covered in the present application, it was found that the reference compound is characterized by inferior retardation activity. It cannot be considered a decomposable retarder; its behavior is typical of that of conventional cationic retarders. On the other hand, the compounds of the present invention are gradually and continually inactivated or hydrolyzed thereby decreasing the retardation effect so that toward the end of the dyeing process, the retarder compounds are virtually completely decomposed and high dye exhaustions are achieved.

Certain heterocyclic compounds, in particular pyridinium salts, as for example, dodecyloxymethylpyridinium chloride and the corresponding octadecyl compound, have also been described [Tenside 2, 76 i965 )]retarders.

SUMMARY OF THE INVENTION In accordance with the process of the present invention, fibrous material consisting of at least predominantly polyacrylonitrile is dyed by immersing the aforesaid fibrous material in an aqueous bath containing a basic dyestuff and up to about percent by weight, relative to the weight of the fibrous material, of at least one member of a group of alkoxymethyl quaternary ammonium compounds, e.g. n-tetradecyloxymethyltributylammonium chloride. The aforesaid alkoxymethyl quaternary ammonium compounds pro vide some unusual and most unexpected effects. For one thing, these compounds retard the dyeing procedure at the outset but as the dyeing proceeds, they are gradually inactivated or hydrolyzed resulting in a decrease in the retardation effect. Thus, towards the end of the dyeing process, these quaternary ammonium compounds are virtually completely decomposed and high dye exhaustions are achieved. In addition to the retardation effect, the decomposition products may have activity as migrating agents and as a result, such compounds may aid in achieving level dyeing through the promotion of dye transfer. The net result is an improved, practical and highly efficient procedure for dyeing fibrous materials.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a new and improved procedure for dyeing fibrous material consisting of at least predominantly polyacrylonitrile which comprises immersing the fibrous material in an aqueous dye bath containing a basic dyestuff in an amount up to about 10 percent by weight, relative to the weight of the fibrous material, of at least one alkoxymethylquaternary ammonium compound of the formula:

wherein R is an alkyl group containing from eight to carbon atoms,

R is propyl or butyl and X is halogen, methyl sulphate or toluene sulfonate.

The fibrous material which is dyed by use of the process of the present invention includes fibrous material consisting essentially of at least 50 percent of polyacrylonitrile and includes copolymers of acrylonitrile with, for example, vinyl compounds such as vinyl alcohol, vinyl acetate, vinyl propionate, vinyl chloride, vinyl bromide, vinylidene chloride, vinyl pyridine, vinyl imidazole, acrylic acid esters, methacrylic acid esters, alpha-chloracrylic acid esters, acrylic and methacrylic acid amides and the like, which contain a considerable and advantageously, a predominant portion of polyacrylonitrile. The fibrous material may also consist of a mixture of polymers containing one or more of said monomers with polyacrylonitrile, the latter material again preferably predominating. lllustrative polyacrylonitrile fibrous materials include, Orlon (particularly, Orlon Type 42 Fiber), Acrilan (consisting of 85 percent acrylonitrile and 15 percent vinyl acetate), and the like.

n-tetradecyloxymethyltributylammonium methyl sulfate n-tetradecyloxymethyltributylammonium toluene sulfonate n-decyloxymethyl-tributylammonium chloride n-dodecyloxymethyltributylammonium chloride n-hexadecyloxymethyltributylammonium chloride n-octadecyloxymethyltributylammonium chloride n-tetradecyloxymethyltripropylammonium chloride n-tetradecyloxymethyltripropyl methyl sulfate n-tetradecyloxymethyltripropylammonium toluene sulfonate n-dodecyloxymethyltripropylammonium chloride n-hexadecyloxymethyltripropylammonium chloride n-decyloxymethyltripropylammonium chloride n-octadecyloxymethyltripropylammonium chloride and the like as well as mixture of these.

Illustrative of the basic dyes which can be used are fuchsin, methyl violet, aniline blue, dyestuffs of the diand tri-arylmethane series, the azine, oxazine and thiazine series, xanthene dyestuffs, acridine dyestuffs, quinoline dyestuffs, quinophthalone dyestuffs, cyanine and methine dyestuffs, basic azoand basic anthraquinone dyestuffs, the indolyland di-indolyl-aryl-methane series, diazine, induline, and the like.

Theretarding agents of the present invention may be used during the dyeing procedure: about 0.025 to 3 percent required with reference to the weight of fiber or other structures of acrylonitrile polymers. The retarding agents may also be used for levelling up after dyeing; in general, larger amounts are required for this purpose that is, from about 1.5 to about 10 percent with reference to the weight of the fiber or other structure, in the blank dye bath. The period for the dyeing varies from about 1% to 8 hours, preferably, the dyeing procedure is between 1 and 3 hours. Similar periods may be used for levelling.

The active retarding agents of the present invention have excellent activity in all dyeings of basic dyestuffs on textile materials such as films, foils, threads, fibers, flocks, fabrics and similar structures of every kind such as, for example, yarns or knitted or woven fabrics which have been made from polymers or copolymers containing acrylonitrile. The fibrous material may be polyacrylonitrile or an acrylonitrile copolymer. The term acrylonitrile polymer is intended to include homopolymers of acrylonitrile and also copolymers which have been prepared from at least about 50 percent acrylonitrile.

With respect to the composition, it may consist entirely of polyacrylonitrile that is, products which are obtainable by polymerization of acrylonitrile alone or in admixture with other polymerizable compounds and which contain at least 50 percent and preferably percent or higher, by weight of acrylonitrile polymerized in the same.

The active retarding agents of the present invention are obtained by a procedure involving preparation of the ether followed by reacting the product thus obtained with the nitrogen-containing or amino compound. I

A typical alkoxymethyl quaternary ammonium compound, n-tetradecyloxymethyltributylammonium compound is prepared as follows:

Tetradecanol (214.4 g.; 1 mole; Alfol l4, Continental Oil Co.) and 34.7 g. (1.1 mole) of paraformaldehyde (95 percent) are combined and heated to 3637 to melt the alcohol. Gaseous anhydrous hydrogen chloride (45.6 g.; 1.25 mole) is added over 1 /2 hour with stirring and cooling to maintain the temperature at 40. The reaction mixture is stirred at 25-40 for 1 hour. At the end of that time the phases are allowed to separate and about 21 ml. of lower aqueous phase is withdrawn and discarded. The organic phase is heated under vacuum at 40 C. for 1 hour or until condensate no longer is obtained. The resulting chloromethyl ether assays about 93 percent by potentiometric titration with standard silver nitrate solution.

Tributylamine (185.3 g.; 1.0 mole) is added dropwise with stirring over min. to the chloromethyl ether. Cooling is required to maintain the temperature at 50 C. The reaction mixture is stirred at 25-30 forl hour. The yield is 448 g. (virtually quantitative) of n-tetradecyloxymethyltributylammonium chloride.

Similarly, using the procedure set out above, except for the replacement of n-tetradecanol by n-dodecanol, the corresponding n-dodecyloxymethyltributylammonium chloride is obtained. In a similar fashion, by replacing tributylamine by tripropylamine, in the above procedure, n-tetradecyloxymethyltripropylammonium chloride is obtained.

The following examples further illustrate the process of the invention but the invention is not to be restricted to such examples. The parts and percentages are by weight and the temperatures are in degrees centigrade, unless otherwise indicated.

A standard dyeing procedure was adopted, which is essentially along the line described by Cohen and Endler (American Dyestuff Reporter 47, 325 (1958).

165 ml of a dye solution of the following composition Color lndex No. 51005 oxazine 1% o.w.o.f. Sodium acetate trihydrate 1% Glaubers Salt 10% Retarder 1.5% pH 4 Liquor ratio :1 about 200F o.w.o.f. on weight of fabric was prepared and heated to boiling in a 3-neck flask equipped with stirrer, reflux condenser and thermometer. The retarder was added (1.5 percent on wt. of fabric) followed shortly by a 5.0 g. sample of prescoured Orlon 42 knit fabric. (The fabric had been prescoured with a nonionic detergent, Triton X-100, as described by Cohen and Endler supra). immediately before the addition of the fabric and at intervals 5, 10, 15, 20, 30, 45, 60, 75, 90,120,150 and 180 min. 2.00 ml. aliquots of the dye solution were removed. These aliquots were diluted to 100 ml. and the optical density at 655 my. (the absorption maximum for CI. No. 51005 oxazine, the dye used in the evaluations) was determined. These data permitted the calculation of percent dye exhaustion at each sampling time. These data, as given in Table 1 below, reflect the dyeing retardation properties of the retarder. The percent exhaustion after 120 minutes (limiting percent dye exhaustion) indicates the ability of the retarder to decompose. Decomposable retarders give higher values of percent dye exhaustion than stable retarders. 1n principle, a decomposable retarder is expected to provide, in the beginning, retardation comparable to the stable, effective retarders. However, as dyeing and retarder decomposition proceed, the retardation decreases until essentially unretarded dyeing obtains toward the end TABLE 1 Dyeing Ex- Limiting Half-Time haustion Dye (min.) 1 hr. Exhaustion None 4 98 Proctors 895* 57.5 54 92 DuPonts LAN" 27 83 94 n-tetradecyloxymethyl 32 92 97 pyridinium chloride n-octadecyloxymethyl- 20 96.5 97.5 pyridinium chloride n-tetradecyloxymethyltributylammonium 100 17 96 chloride n-dodecyloxymethyltributylammonium 79 19 94 chloride Apparently a mixture of C,,C alkyl dimethylbenzylammonium chloride A stearyl trimethylammonium halide [probably ammonium bromide].

These data demonstrate the unique behavior of the retarders of the present invention showing early retardation and a gradual increase in dye exhaustion with dyeing time.

There is other evidence of retarder decomposition.

Samples of Orion fabric dyed with Color Index No. 51005 oxazine with the use of Proctors 895 retarder, could not be satisfactorily overdyed with Maxilon Super Black OLN whereas fabric samples retarded with present retarder compounds, e.g. n-tetradecyloxymethyltributylammonium chloride were satisfactorily overdyed.

In these tests the activity and behavior, i.e., retardant activity, of tetradecyloxymethyltripropylammonium chloride was found to be quite similar to the corresponding tributyl compound.

What is claimed is:

l. A method of dyeing fibrous material consisting at least predominantly of polyacrylonitrile which comprises immersing the fibrous material in an aqueous dye bath containing a basic dyestuff and from about 0.025 to about 10 percent by weight, relative to the weight of the fibrous materials, of at least one alkoxymethyl quaternary ammonium compound of the formula wherein R is an alkyl group containing from eight to 20 carbon atoms,

R is propyl or butyl,

X is halogen, methyl sulphate or toluene sulfonate.

2. A process according to claim 1, wherein the fibrous material consists entirely of polyacrylonitrile.

3. A process according to claim '1, wherein the fibrous material consists of a polyacrylonitrile copolymer.

4. A process according to claim 1, wherein the alkoxymethyl quaternary ammonium compound is present in an amount between about 0.025 and 3 percent.

gredients, a basic dyestuff and from about 0.025 to about 10 percent by weight, relative to the'weight of the fibrous material to be dyed, of at least one alkoxymethyl quaternary ammonium compound of the formula wherein R is an alkyl group containing from eight to 20 carbon atoms,

R is propyl or butyl,

X is halogen, methyl sulphate or toluene sulfonate;

9. An aqueous dye bath composition according to claim 8, wherein the alkoxymethyl quaternary ammonium compound is present in an amount between about 0.025 and 3 percent.

10. An aqueous dye bath composition according to claim 9, wherein the alkoxymethyl quaternary ammonium compound is n-tetradecyloxymethyltributylammonium chloride.

11. An aqueous dye bath composition according to claim 8, wherein the alkoxymethyl quaternary ammonium compound is n-tetradecyloXymethyltripropylammonium chloride.

12. An aqueous dye bath composition according to claim 8, wherein the alkoxymethyl quaternary ammonium compound is n-dodecyloxymethyltributylammonium chloride. 

1. A method of dyeing fibrous material consisting at least predominantly of polyacrylonitrile which comprises immersing the fibrous material in an aqueous dye bath containing a basic dyestuff and from about 0.025 to about 10 percent by weight, relative to the weight of the fibrous materials, of at least one alkoxymethyl quaternary ammonium compound of the formula wherein R is an alkyl group containing from eight to 20 carbon atoms, R'' is propyl or butyl, X is halogen, methyl sulphate or toluene sulfonate.
 2. A process according to claim 1, wherein the fibrous material consists entirely of polyacrylonitrile.
 3. A process according to claim 1, wherein the fibrous material consists of a polyacrylonitrile copolymer.
 4. A process according to claim 1, wherein the alkoxymethyl quaternary ammonium compound is present in an amount between about 0.025 and 3 percent.
 5. A process according to claim 1, wherein the alkoxymethyl quaternary ammonium compound is n-tetradecyloxymethyltributylammonium chloride.
 6. A process according to claim 1, wherein the alkoxymethyl quaternary ammonium compound is n-tetradecyloxymethyltripropylammonium chloride.
 7. A process according to claim 1, wherein the alkoxymethyl quaternary ammonium compound is n-dodecyloxymethyltributylammonium chloride.
 8. An aqueous dye bath composition for dyeing of fibrous material consisting at least predominantly oF polyacrylonitrile and containing, as essential ingredients, a basic dyestuff and from about 0.025 to about 10 percent by weight, relative to the weight of the fibrous material to be dyed, of at least one alkoxymethyl quaternary ammonium compound of the formula wherein R is an alkyl group containing from eight to 20 carbon atoms, R'' is propyl or butyl, X is halogen, methyl sulphate or toluene sulfonate.
 9. An aqueous dye bath composition according to claim 8, wherein the alkoxymethyl quaternary ammonium compound is present in an amount between about 0.025 and 3 percent.
 10. An aqueous dye bath composition according to claim 9, wherein the alkoxymethyl quaternary ammonium compound is n-tetradecyloxymethyltributylammonium chloride.
 11. An aqueous dye bath composition according to claim 8, wherein the alkoxymethyl quaternary ammonium compound is n-tetradecyloxymethyltripropylammonium chloride. 